Means for removing molded slugs from molds



'April 12, 1949. J. B AlLEY MEANS FOR REMOVING MOLDED SLUGS F'ROM MOLDS 3 Sheets-Sheet 1 Original Filed Jan. 15, 1942'.

Inventor: JamesBailgy 19 Mz Aziorngys.

hll'fness:

April 12,1949. AILEY 2,467,107

MEANS REMQVING MOLDED SLUGS FROM MOLDS In ven tor: Jam e5 Bailgy witnes Q g 4? M 4.4M Atforne ys,

April 12, 1949. J, BAlLEY I 2,467,107

MEANS FOR REMOVING MOLDED sLUcTS FROM MOLDS Original Filed Jan. 15, 1942 a Shets-Sheet 3 M Q N 0% Q E S w k-i In 0 en for: Jam e5 Bail y Witness: I 4

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Patented Apr. 12, 1949 MEANS FOR REMOVING MOLDED SLUGS FROM MOLDS James Bailey, West Hartford, Conn., assignor to Plax Corporation, Hartford, Conn., a corporation of Delaware Original application Janliary 15, 1942, Serial No. 426,814. Divided and this application May 15, 1944, Serial No. 535,596

2 Claims.

1 The present invention relates generally to the manufacture, by injection molding, of plastic objects or slugs of large cross sectional area and of considerable length, and has particular reference to means for removing the molded slugs from the molds.

The present application is a division of my application, Serial No. 426,814, filed January 15, 1942 now abandoned and entitled Method of and apparatus for injection molding.

The aim of the invention is to provide a simplified and economical arrangement by means of which molded objects or slugs may be drawn quickly, easily and safely from the molds at the completion of the molding operations and with-' out danger of injury to the molds or the molded slugs.

Other objects will be in part obvious, and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set forth and the scope of the application of which will be indicated in the appended claims.

Referring to the accompanying drawings, wherein is shown one embodiment which the present invention may take:

Figure l is a plan view of so much of an injection molding apparatus as is necessary to illustrate the features of the present invention;

Fig. 2 is a top plan view of the power means for drawing the slugs from the molds and the support along which the power means may be adjusted; this figure, when placed to the right of Fig. l, constituting a continuation thereof;

Fig. 3 is an end view of the structure shown in Fig. 2;

Fig. 4 is a top plan view of the power means on a somewhat larger scale; and

Fig. 5 is a side view of the power means shown in Fig. 4.

Referring to the drawings, the apparatus is shown as having a stuffer A, only a portion of which is illustrated, as the same may be of any suitable construction. The stuffer may be. of the type having a casing Ill through which the heated plastic compound is forced by a driven screw l2. The stuffer has an outlet 14 which communicates with the inlet N5 of a distributingmanifold B,

which is disclosed in detail in said application Serial No. 426,814. The manifold has a distributing channel (not shown) which delivers to a plurality of outlet pipes or nipples l8 and the flow of the heated plastic material from the distributing channel to the respective nipples is controlled by shut-off valves indicated generally by the numeral 20. The molds C have their inlet ends respectively connected to the delivery ends of the nipples or pipes l8. Each of these molds is of considerable length and of relatively large cross section. Each of the molds is provided with a jacket 22 having an inlet 24 and an outlet 26 to permit the passage of fluid about the molds for the purpose of heating the same, and, if desired, for cooling them. Usually, the mold is kept hot until it is filled with the plastic material and then the mold isgradually cooled. 7

Due to the fact that the molds are of considerable length and are of large cross sectional area, difficulty has been experienced in removing the slugs therefrom, especially when the slugs are formed of compounds which adhere very closely to the mold wall, such, for example, as polystyrene and methyl methacrylate. The adherence of compounds of this nature to the molds is unusually strong when the compounds are injected into a hot mold.

In order to facilitate removal of the slugs from the molds, each of the molds is provided at its outer end with a removable closure member Ell with which is associated a pull member D of such character that one end thereof, during the molding operation, will become embedded and fixed in the end of the slug, but the pull member may be readily removed from the slug following the Withdrawal of the slug from the mold. The closure member 30 for each mold comprises a plate which may be removably secured in place by bolts 32. These bolts pass through aligned openings in theclosure plate 30 and a flange member 34 p which may be screwed onto the outer-end of the mold. The pull member D has' a stem or pin portion 36 ,provided at one end with an enlarged, tapered, threaded head 38 and at its other or outer. end with a yoke 48. The stem or pin portion 36 slidably extends through a centrally disposed opening 42 in the closure plate. The stem 0r' pin 36 is longer than the thickness of the closure plate so that the pull member may have a limited longitudinal movement with respect to the closure member. The arms of the yoke 40 are provided with aligned openings adapted to receive a cross pin 46 for securing the pull member to one end of a chain 48 of a pulling device or winch'E, later described more in detail. The end of the chain has a link 49 provided with a hole for receiving the cross pin.

With the pullmember constructed in, the manner described; thexplastic, upon being forced into the mold, will form around the threaded tapered surface of the head 38 and, upon cooling, will become rigidly secured thereto. Due to the tapered conical shape of the head,.'thenipla'stic will form thereon without setting up strains which might result in breakage of. the..slug when the latter is removed from the moldl' During. the molding operation, the plastic, which is, of course, forced under pressure into the mold, will press the head against the closure-member filland thus leakage of the plastic throughthe 'hole'42 is prevented. After the molding operation has been completed, the plastic is cooled in the mold and the slug will tend T to foreshorten with the result that the -head? 38 will be drawn inwardly, and' this can take place because the: stem *3B of the pull member is.-of*sufiicient lengtlnto compensate forshrinkage of theplasticmaterial. .After the molded slug-has been cooled inthe mold sufficiently --to retain itsshape; upon: --removal, the bolts :32 are removed, and-the link- 4'9.

on :the end-- ot-the chain flds connected to the yoke 40 by means-of the-cross pin 46; The power device 'or .winch E is-thenoperated to. exert a pull on the slug longitudinally otjtheemold and outwardly thereoiiwith ithekre'sfult'that theQslug is withdrawn from thermold. After the slug has been withdrawn from the mow, the. pull'member is removed by merely'turning it so a'sto screw the head 38 out of the reces'sin which it had been embedded. p i I The winch Econsists". of a frame-having side members 50 interconnected at its forward endby a cross member 52 and at: its rear end by a cross member 54. "The side members 5llprovide sup= ports for a transverselyextending'shaft 56 upon which there is carried intermediate of the side members aspro'cket 58'over-which the sprocket chain 48 passes, and also a relatively large-"gear 60; said 'gear and'sprocket being secured to the shaft for simultaneous-"rotation. Q i

Forwardly of the shaft 56 there is" further car-- ried by the side members a second shaft GZupon which there is carried a relatively small gear 64 meshing with gear lifli 'I'he s'h'aft'BZ' extends outwardly beyond the ends of the side members and carries adjacent each 'side member a ratchet 65 adapted to cooperate with'a pawl 68 to prevent backing up of the shaft when the latter has "been turned in a direction'toexert a pull on the mom;

To operate the shaft 62; each end is'made of rectangular cross section and has a pin IO-therethrough for-cooperating with the rectangular slotted socket;'l2-'of'a-rcrank- 1'4. With this construction it will be seen" that by rotating the shaft 62 the-relatively-small-gear 64 will rotate the gear 60 and thesprocket 58 to exert a pull on the chain 48. Due to the mechanical advantage obtained because of thepdifierencesvinthe-size of thee-gears, a. tremendous pullemay be exerted which ,wilLbrea-k the slugs,;f rom the molds, per: mitting their removal. Aitentheslugshavebeen removed; it will -be --apparent that the closure member- 3flmay -be readily removed from the'end of the slug by merely rotating the pull member D to unscrew the head 38.

In order to utilize one winch for all of the molds, the winch is carried by a slide or anchor member which is mounted for adjustment on a transversely extending track disposed generally in the plane of the molds at a distance beyond the discharge ends thereof. The track is here shown, for illustrative purposes, as comprising two horizontally arranged channel beams inverted relative to one another and spaced apart so as to provide a guideway 82 therebetween. The track may be supported in any suitable manner; for example, one end may be secured to a wall 84 and the other end to a framework 86. The rear cross member seer the winch is provided with rearwardly extending ears 88 adapted to fit above and below an earQlJlextehdin'g forwardly from a guide plate 92 ofthevanchor member. The ears 88 and are provided with aligned vertical openings for receiving, apivot pin 94 for pivotally mounting thexwinch on the anchor member. The guide plate 92 is provided with top and bottom ribs orrunners 96which are respectively adjacent the upper and lower edges of the front vertical flanges of the channel-beams 80. .The anchor member has a flat arm 98 extendingrearwardly'from the guide plate 82 -and positioned within the guide.- way .82.. Theanchor member is secured in any desired positionaof adjustment on the track by a bolt I00 and a second guide plateslln. This second guide plate engages-against-the rear faces oi therear vertical: flanges of the beams 88 and has top "and-.bot'tom runners" I84 corresponding to the runners 96.; one. boltzextends-throug'h a central opening Iin this guideplate and is screwed into the rearend of the stem or arm-98. -With the arrangement. described,- it will be-seen that the anchor member,- together with the winch carried thereby; maybe moved longitudinally of the track to any selectedposition where the winch issubstantiallyin alignment with the mold from which theslug is to be withdrawn. This can be done by merely loosening the bolt I00, moving the anchor member to the desired "position, and thensecuring itgin-the selected; position by again tightening the'boit: v i 5, V. As many changes-could be made in the above c nstructior 1 andmany apparently widely different embodimentsfofj thisjinvention could be made without departing fromthe scope thereof, it is intended that all matter contained in the above description or shownin the accompanying drawings shall be interpreted as illustrative and not in a limitingsense.

It is also to be understood that the language used in thefollowing claims isintended to cover all of the generic and specific -features of the in-' vention herein described and all statements of the scope of the-invention which, as a matter of language, 'mlghtibe said to fall therebetwen.

I claim as my invention v 1. In combination, a mold into the forwardend of which plastic material is adapted" to be injected and from the outer end of which the formed plastic slug is adapted to be withdrawn, means for injecting heated'plastie material intothe forward end of themoldfa closure 'plate for closing the'outervend of the mold and having a central opening, means for removably clamping said plate against the outer-end or the" fnold; "and 'a' pull member car-ri'ed ="by, said 'plate'and having a: pin

' slidably mounted in and of longer length than said holein-the closure member, a tapered threaded head on the inner end'Of sa'id pih'andab'o'ut which the plastic material is adapted to be molded, and a coupling member on the outer end of said pin for connection to power means.

2. In combination, a mold into the forward end of which plastic material is adapted to be injected and from the outer end of which the formed plastic slug is adapted to bewithdrawn, means for injecting heated plastic material into the forward end of the mold, a removable closure device for the outer end of the mold, and a slug engaging member extending into said mold through an Opening in said device and axially movable with respect thereto, said member having an inner portion adapted to be imbedded in the molten plastic when the same is injected into the mold and being free to move inwardly during subsequent cooling and shrinkage of the slug to retain said inner portion in said imbedded condition, said innerportion being of greater cross section than said opening whereby said portion will abut against the closure device to limit outward movement of the member and to conceal said openin when molten plastic is injected into the mold.

JAMES BAILEY.

REFERENCES CITED The following references are of record in the file of this patent: 

